<title>最长公共子串长度</title><link href="http://hzoi.com/tomorrow.css" rel="stylesheet"><div class="ui existing segment"><pre><code><span class="pl-cp">#include</span> <span class="pl-cpf">&lt;iostream&gt;</span><span class="pl-cp"></span>
<span class="pl-k">using</span> <span class="pl-k">namespace</span> <span class="pl-n">std</span><span class="pl-p">;</span>
<span class="pl-kt">int</span> <span class="pl-n">a</span><span class="pl-p">[</span><span class="pl-mi">1005</span><span class="pl-p">],</span> <span class="pl-n">b</span><span class="pl-p">[</span><span class="pl-mi">1005</span><span class="pl-p">],</span><span class="pl-n">dp</span><span class="pl-p">[</span><span class="pl-mi">1005</span><span class="pl-p">][</span><span class="pl-mi">1005</span><span class="pl-p">];</span>
<span class="pl-kt">int</span> <span class="pl-nf">main</span><span class="pl-p">()</span> <span class="pl-p">{</span>
    <span class="pl-n">string</span> <span class="pl-n">sa</span><span class="pl-p">,</span> <span class="pl-n">sb</span><span class="pl-p">;</span>
    <span class="pl-n">cin</span> <span class="pl-o">&gt;&gt;</span> <span class="pl-n">sa</span> <span class="pl-o">&gt;&gt;</span> <span class="pl-n">sb</span><span class="pl-p">;</span>
    <span class="pl-kt">int</span> <span class="pl-n">na</span> <span class="pl-o">=</span> <span class="pl-n">sa</span><span class="pl-p">.</span><span class="pl-n">size</span><span class="pl-p">();</span>
    <span class="pl-kt">int</span> <span class="pl-n">nb</span> <span class="pl-o">=</span> <span class="pl-n">sb</span><span class="pl-p">.</span><span class="pl-n">size</span><span class="pl-p">();</span>
    <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span> <span class="pl-o">=</span> <span class="pl-mi">0</span><span class="pl-p">;</span> <span class="pl-n">i</span> <span class="pl-o">&lt;</span> <span class="pl-n">na</span><span class="pl-p">;</span> <span class="pl-n">i</span><span class="pl-o">++</span><span class="pl-p">)</span><span class="pl-n">a</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-o">+</span><span class="pl-mi">1</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-n">sa</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]</span> <span class="pl-o">-</span> <span class="pl-sc">&#39;0&#39;</span><span class="pl-p">;</span>
    <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span> <span class="pl-o">=</span> <span class="pl-mi">0</span><span class="pl-p">;</span> <span class="pl-n">i</span> <span class="pl-o">&lt;</span> <span class="pl-n">nb</span><span class="pl-p">;</span> <span class="pl-n">i</span><span class="pl-o">++</span><span class="pl-p">)</span><span class="pl-n">b</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-o">+</span><span class="pl-mi">1</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-n">sb</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]</span> <span class="pl-o">-</span> <span class="pl-sc">&#39;0&#39;</span><span class="pl-p">;</span>
    <span class="pl-kt">int</span> <span class="pl-n">k</span><span class="pl-o">=</span><span class="pl-mi">0</span><span class="pl-p">,</span> <span class="pl-n">maxv</span><span class="pl-o">=</span><span class="pl-mi">0</span><span class="pl-p">;</span>
    <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span> <span class="pl-o">=</span> <span class="pl-mi">1</span><span class="pl-p">;</span> <span class="pl-n">i</span> <span class="pl-o">&lt;=</span> <span class="pl-n">na</span><span class="pl-p">;</span> <span class="pl-n">i</span><span class="pl-o">++</span><span class="pl-p">)</span> <span class="pl-p">{</span>
        <span class="pl-k">for</span><span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">j</span> <span class="pl-o">=</span> <span class="pl-mi">1</span><span class="pl-p">;</span> <span class="pl-n">j</span> <span class="pl-o">&lt;=</span> <span class="pl-n">nb</span><span class="pl-p">;</span> <span class="pl-n">j</span><span class="pl-o">++</span><span class="pl-p">){</span>
            <span class="pl-k">if</span><span class="pl-p">(</span><span class="pl-n">a</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]</span><span class="pl-o">==</span><span class="pl-n">b</span><span class="pl-p">[</span><span class="pl-n">j</span><span class="pl-p">])</span>
                <span class="pl-n">dp</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">][</span><span class="pl-n">j</span><span class="pl-p">]</span><span class="pl-o">=</span><span class="pl-n">dp</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-o">-</span><span class="pl-mi">1</span><span class="pl-p">][</span><span class="pl-n">j</span><span class="pl-o">-</span><span class="pl-mi">1</span><span class="pl-p">]</span><span class="pl-o">+</span><span class="pl-mi">1</span><span class="pl-p">;</span>
            <span class="pl-n">maxv</span><span class="pl-o">=</span><span class="pl-n">max</span><span class="pl-p">(</span><span class="pl-n">maxv</span><span class="pl-p">,</span><span class="pl-n">dp</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">][</span><span class="pl-n">j</span><span class="pl-p">]);</span>
        <span class="pl-p">}</span>
        <span class="pl-n">k</span><span class="pl-o">=!</span><span class="pl-n">k</span><span class="pl-p">;</span>
    <span class="pl-p">}</span>
    <span class="pl-n">printf</span><span class="pl-p">(</span><span class="pl-s">&quot;%d&quot;</span><span class="pl-p">,</span><span class="pl-n">maxv</span><span class="pl-p">);</span>
<span class="pl-p">}</span>
</cpde></pre></div>